GS Radiator FAQ
compiled & edited by
Kristian #562
Please read the Disclaimer before attempting any work in this FAQ.
Updated 15 August 2004
Radiator Leak
by Kristian #562
While there has been quite a number of instances, so
far this hasn't been that much of a widely reported
problem and it would appear to affect mainly early bikes.
BMW must have decided to tighten their Q.C.
Having said that, Michael McKeon from NZ notes:
On a recent BMW New Zealand "adventure" ride it was
pointed out to me that the small stones, typically used on gravel
roads here, can become trapped behind the plastic radiator
shrouds on the fuel injected 650 and over time rub through the
radiator. This has apparently happened to some NZ 650's. I use my
Dakar on gravel a lot and sure enough, at 16,000 km it had 4-5
stones sitting there. Something easily checked by removing the
plastic radiator shrouds.
Radiator Leak Experiences:
- 01/01 GS. Got to work this AM
and noticed some spots of liquid on my boot. Right top
portion of radiator is leaking. When I touch the area
with a rag it is wet with antifreeze. Can I ride it the
20 highway miles home. Going up to 65F in Philly today.
Ron #762
- Had the same problem and the
rad was covered under warranty. If you are only going
twenty miles or so and your bike is not running hot (warning
light turns on) you should be fine. If the warning light
is showing that your bike is overheating, add some water
or antifreeze to the rad and drive it to the dealership.
The problem with the GS is that you need to take the
cover off to get to the radiator to fill it up (5 min job).
Steve#780
- '01GS With 8500 miles the
radiator started to leak. No visible damage. Canton
Cycles in CT did an order and replacement with a 3 day
total turnaround. An excellent dealer. Zero cost, under
warranty. JimG#637
- I had the same problem
however I had noticed a small coolant loss since day one.
It finally got bad enough that the bike was running
warmer. I don't think this is uncommon. I think they got
some bad radiators from the vendor. Vendor is not an
excuse it is a reality. The instances I read here were
all happily and quickly repaired under warrantee. No
excuses. But the reality of the situation is I think they
got so bad radiators. BMW doesn't make them. So they must
have gotten some bad ones from a vendor. These are
machines and machines are not perfect unlike the people
who buy them who seem to be. Supertech
- I have a 2000 GS Dakar and
have somehow ended up with a pinhole in the radiator, not
a stone. My dealer says that he has enquired around and
they do not have much success with repairing radiators.
My local cooling shop says no problem the pin hole can be
fixed with epoxy so I have tried that. My question is, is
their a history of radiator failures in Dakars and is
there a history of unsuccessful repairs or is my dealer
who has only just been appointed locally pulling my leg.
Dodgy, Australia
- Here in the US some radiators
have failed. Including mine. Dealer replaced it under
warranty. No problem. You may have different warranty
than we do here. As my leak started while I was on the
way home from Alaska in really the middle of nowhere, I
poured in some stop leak I bought at a small store.
Sealed up fine. I'm not sure I would have replaced it if
I had to spend my money for it. ciao Tony Homeless
- ' 00 GS. OK, mine's gone.
Dripping on LHS Top looking forward. Just 7000 km's on
the bike. Can anyone else put their hand up and say yup
happened to me too. Kristian #562 (HK).
- 10/01 Dakar Oregon. Had mine
replaced under warranty. Around 11k miles I think but
mine lost coolant since day one. Very slight amount. Leak
finally got big enough to find. No rock chips. I now have
screen over my new one however. Steve #1130
- I had mine replaced under
warranty at approx. 22000km. The leak appeared near one
of the mounting bolts at a weld point. Andre, Whistler,
BC #1119
- Mine leaked at 5,000 miles
and was replaced under warranty 01/01 build. Ron#762
- 01/01 pin hole leak in core,
replaced at about 4500 miles. BradG#1002
- F650 GS- build Jan. 00. Not
what you asked for-- no leaks yet, despite a radiator
that is diagonally askew. At the top it is 1,5 cm to the
left- relative to the frame and at the bottom just 0,3 cm.
Top left lug nearly ripped off the radiator, but after
some 9k miles after it happened, still no leaks. Only
thing on my GS that has been a lot better than I expected
from a BMW. Haakon #626.
- Me too! I got it replaced
under warranty after a radiator shop said that it was
defective. I think I got 12,000 miles out of mine before
it started to leak, in two places. There was also no
indication that the radiator had been struck by anything
around the area that was leaking. If the radiator is
struck my a rock, etc. and it leaks, well then its not a
warranty. PS the replacement has been good. Hot over 26,000
miles on her now. Dave # 717
- Leak in core, replaced under
warranty. Approx. 9500 miles. JimG#637
- My 99 Dakar sprung a leak top
right side at 13000K's, no stone marks. I posted a
message here for suggestions and the consensus seemed to
be replace it rather than repair it. I had the radiator
out so took it to the local radiator shop and they said
they could fix it with epoxy guaranteed. I took the
chance and it seems OK after another 2000 K's including a
long 1000K trip two weeks ago. Not hard to pull out and
replace if it goes again. Seems from the replies to my
original posting that it is not an uncommon problem. The
local dealer was not much help as they are newly
appointed and don't have much experience with BMW's.
Ratso, Australia.
- My '01 F650GS had a defective
radiator that got replaced under warranty about 12,000
miles ago. Today was a very hot day in the South West..
115 +/-. While riding home to San Diego from Yuma my
radiator warning light went on and when I exited the
freeway I noticed the radiator over flowing. Took off the
top box, saddle and then removed the six bolts securing
the left side panel and refilled the over flow tank with
drinking water that I was carrying. Tried to continue but
the warning light would go on after about 3 minutes of
riding, so I would turn it off, let her cool down and
then try again. Well this made the next 20 miles take
about 2.5 hours. Got the bike off the desert floor and to
a gas station that is at about 4,000 ft and probably 30
degrees cooler. Found the over flow tank was full but
after waiting about an hour after hosing down the bike I
took off the radiator cap off and found the radiator
looking empty. Therefore the radiator fluid in the over
flow tank was not flowing back into the radiator which
caused the constant over heating. Topped off the
radiator, sealed it with the radiator cap and was able to
make it home ..about 70 miles. The only problems I have
had with my F650GS have been relating to the cooling
system/ radiator. Is anyone else having similar problems?
Has BMW issued any modifications, recalls to this area of
the bike? When the radiator fails it is usually hot
outside, and when the temperature gets up to 115 it can
be life threatening to have prolonged exposure. This is a
very dangerous problem. Dave # 717.
- Just for statistics: Now my
radiator is also leaking (F650GS 05/00 20500 km [about
13200 miles]). I will tell you if it will be repaired
under guarantee. Robert #1071.
- I recently found a tiny weep
in my 00GS radiator, 40,000k's, on returning from a trip.
Not much fluid was being lost, and it looked like impact
damage as the cooling fins were damaged around it. After
cutting away the damaged fins, cleaning really well with
Goddard's Glow aluminium polish on a toothbrush, I
patched it with a Loctite product, a radiator/petrol tank
repair material, epoxy ribbon, which sets like rock.
Worked great for about 2000 k's, then saw the green
coolant weeping again. I picked out the repair material,
cleaned up the site even better, and found a tiny
hairline fracture about 5mm long along the top of the
tube which was leaking. Took it to one of our larger
radiator repair shops who said he repairs quite a few
aluminium bike rads. When I picked it up, it had been
welded and also covered with an epoxy material. Pressure
tested, no leaks. Went on another trip, keeping a close
eye on it, on the way back, after about 1500k's, sure
enough it was just starting to show leaking fluid again.
It's cool weather here at present, and the engine is
running pretty cool, so again no fluid lost. Went back to
the radiator repair shop who said that most of their
repairs work 100%. They gladly refunded me my money for
the repair, and I have brought a new rad, AUD260- which
they reckon was good value, comes with the thermostat
& cap. They said some of the japper rads can be about
$1000. Apparently the problem with using any epoxy is
that the expansion rate of the repair material must match
the rate of the aluminium radiator, or they will
eventually part company. I reckon the Loctite stuff was a
great emergency repair, and now carry the rest of the
ribbon in case it's needed. I have also made a set of
stone guards, dead easy. Remove the two air scoop
thingies from in front of the rad, and make a cardboard
template for each side (they are different sizes). Next
down to your friendly hardware store, look in the section
where they sell plastic vents that you put up under the
eaves of your house for ventilation. I found one about
350mm by 250mm, which gave me enough material to cut two
pieces out. Next is to drill two holes in each air scoop,
in the horizontal rib which goes across the middle of
each scoop. Use small ( about 150 to200 mm long)
electrical cable ties, or Ziploc's, to secure the guards
from the inside out. I will post a pic of these when
developed. Most of these type of vents are white plastic,
so you have to spray paint. Hope this is of help, and the
post is not too long. Fitzy in OZ.
- I had a radiator leak/spill
and it turned out to be a cracked radiator mount that
also cracked into the radiator. All covered under
warranty and replaced, F.O.C. The tech said the vibration
of a thumper like this could easily cause such a problem.
NancyK #764
- First, a little background:
Discovered pinhole leak in radiator. Added coolant.
Continued riding with leak. Week later, coolant temp
light came on. Rode for 0.25 miles. Found coolant level
very low (D-Oh!). Refilled. Now for the good stuff:
Discovered light-colored goo inside the oil filler cap
and inside-top of oil tank. Checked weep hole. Perfectly
dry. Replaced oil in oil tank and engine sump (but not
filter). I'm scheduled to get the radiator replaced at
the dealer in a few days. 21K miles, radiator leak,
replaced under warranty. No protector installed. I
checked for a rock strike - there was none. And the
mechanic checked even more thoroughly than I did before
he approved the repair under warranty. The leak occurred
in the highest cross-tube(?). It would be tough for a
rock strike to hit up there. Raymo #1173.
- Two weeks in NM and CO, two F650GSes,
three cooling system problems. #731's cooling fan failed
to come on when needed in Carlsbad traffic; we got it
shut down immediately after it spewed coolant so no heat
damage as far as we know. #732's coolant hose came loose
from the engine nipple and pumped all coolant from the
system; a road side fix on this one (strongly recommend
replacing those stupid clip clamps BMW uses with
legitimate hose clamps at home before one comes unclipped
on you at the side of the road--this fix will cost you
less than $3 and possibly prevent the scalding of your
left leg). Later, #732's radiator sprang a weepy leak at
the upper left corner. Both the fan and radiator were
replaced under warranty. Big thanks to Santa Fe and
Foothills (Denver) BMW shops respectively for emergency
care (but wouldn't it be nice if dealers still stocked
parts!). Warranties are nice, but they don't give you
back your vacation. The cooling system and history of
problems are discussed in the FAQs. I just wanted to be
added to the tally. Maybe there will be a better radiator/fan
replacement sometime soon. And don't forget to put some
real hose clamps on your coolant hoses. Bernhard#732
- I was at the Finger Lakes
Rally in New York state this weekend. While on a ride I
met a rider at Hammondsport NY who was riding a yellow F650GS.
He had the the left faux tank panel strapped to the
pillion seat to keep an eye on the leak. He fixed the
leak with "Stop Leak" or something like that. I
hope the fellow made it home ok. Rodger#1046
- I didn't want to whine, but
add us to the list too. One of our rads sprang a leak a
couple of weeks ago. Missing grommet that allowed the rad
to rub against the frame. Wore through. Shelley798.
- Two weeks in NM and CO, two F650GSes,
three cooling system problems. #731's cooling fan failed
to come on when needed in Carlsbad traffic; we got it
shut down immediately after it spewed coolant so no heat
damage as far as we know. #732's coolant hose came loose
from the engine nipple and pumped all coolant from the
system; a road side fix on this one (strongly recommend
replacing those stupid clip clamps BMW uses with
legitamate hose clamps at home before one comes unclipped
on you at the side of the road--this fix will cost you
less than $3 and possibly prevent the scalding of your
left leg). Later, #732's radiator sprang a weepy leak at
the upper left corner. Both the fan and radiator were
replaced under warranty. Big thanks to Santa Fe and
Foothills (Denver) BMW shops respectively for emergency
care (but wouldn't it be nice if dealers still stocked
parts!). Warrenties are nice, but they don't give you
back your vacation. The cooling system and history of
problems are discussed in the FAQs. I just wanted to be
added to the tally. Maybe there will be a better radiator/fan
replacement sometime soon. And don't forget to put some
real hose clamps on your coolant hoses. #732
- I was at the Finger Lakes
Rally in New York state this weekend. While on a ride I
met a rider at Hammondsport NY who was riding a yellow F650GS.
He had the the left faux tank panel strapped to the
pillion seat to keep an eye on the leak. He fixed the
leak with "Stop Leak" or something like that. I
hope the fellow made it home ok. Rodger#1046
- I didn't want to whine, but
add us to the list too. One of our rads sprang a leak a
couple of weeks ago. Missing grommet that allowed the rad
to rub against the frame. Wore through. Shelley#798
- I now have my bike in the
shop for similar cooling system problems. I've roached
two fans with my bike, and multiple fuses. Bike still
gets hot at speed. Water Pump? Radiator? both? Chris.
- I had this exact thing happen
to me this winter. Only it wasn't my stone - it was from
the previous owner. With the vibration, the pebble worked
a groove in the radiator behind the frame. it was about 2"
long before it caused a leak. chppdlvvr, 2001 F650GS,
Aurora, CO.
- After ~3600 miles my 2001 GS
sprung a leak on my Christmas morning cinnamon roll
delivery route. Got my left ankle all wet at highway
speeds. The bottom 2 rows on the left side of the
radiator were full of coolant/water (on the sidestand)
and we couldn't find any visible damage after removing
the left cover. My oil cap also has white foamy stuff in
it, but there are only a few bubbles in the oil tank. I
did hop a big curb before I noticed the leak, but that
shouldn't have done anything to the radiator- it did jolt
the rider quite a bit- I keep forgetting about the whole
cold vs suspension thing....... Turns out that there was
a small rock lodged in between the radiator and the frame.
It had been there for quite a while and had just worked
its way in with all the vibration. The last straw was
probably that big curb... whoops. Anyway, they still
replaced it for free since I just bought it. Score one
for the shop. Next on the list: radiator guards... this
bimmer is spendy. The oil leak I had over the right
sidecover was a disconnected crankcase breather tube. Now
I know what to look for... (chppdlvvr).
- Since I've always found you
guys to be a wealth of knowledge, I was hoping you might
be able to post a couple of lines on my problem: the
temperature light has come on for my F650GS after 15
minutes of riding the bike. Second day in a row this has
happened, I just wanted to make sure (duh!) that it
wasn't a bad dream. Stopped the bike RIGHT away. I
checked the coolant yesterday; it was down, I admit--but
not below the min. level. This has happened in the past;
but I wasn't sure it was leaking, figuring it is hotter
than hell in Texas and losing some coolant was just
natural in 100 degree Fahrenheit weather. So I've been
keeping a close eye on it; the other complication is a
couple of times, here and there--but only a couple of
times, like once when starting up-- I've smelled that
sweet smell of burning coolant that somehow got on to a
hot pipe somewhere. No signs of leaks, upon superficial
observation. The rad has been replaced once, but no
problem since then. Topped coolant up yesterday, and
voila--same problem today. I've got 10W/30 oil in it that
I'd planned to change this weekend. What are the possible
causes for this light to come on? And what skill level is
required for the repair? I'd be grateful, as always, for
your thoughts. Sarah.
- Sarah: I have seen this on my
bike and others. You need to have someone pressure check
your radiator and I bet you find the problem. There a
number of the new G/S's with pin sized holes in the
radiators. Not enough to show a leak. The coolant goes
away slowly. Mine did it since day one. Unlike others I
have not seen the waterpump problems you read about here
and I see a lot of these bikes. I am sure the problem is
real but I haven't seen it. Stuportech
- I was riding to work this
morning, and noticed a fair bit of steam coming from the
right hand side of the bike. First I thought the bike
might just be boiling off some water (a bit wet downtown).
But I pulled over to have a look, and found a fair bit of
blue liquid coming from the top right attachment tab on
my rad. Took it home, ripped off all the bits, hoping it
was something obvious like a loose hose. No luck. Rode to
my dealer, and confirmed: dead rad, new one is being
ordered. It seems to have cracked right where the
attachment tab is welded onto the radiator. One thing I
noticed when I was waiting at the dealer: The newer GS's
seem to have a redesigned rad mount. On my bike, the tabs
which mount the rad are about 1.5 cm (3/4 inch?) wide. On
the newer bikes (ones I saw) the tabs are welded on about
10 cm (4 inches) wide. Rad was covered under warrantee.
New rad has the mounting tabs welded all the way along
the top (rather than just the 3/4 inch welds on the
original). If you have an 01 GS with the small tabs, you
may want to try to get it replaced. This design has
proven to have flaws. Ted in TO
- I went with the standard GS.
I have a 2001, and had some surging issues until I got
the software updated to the latest level. Oh, I had one
other prob. The radiator started leaking on mine, right
where the mounting tabs were welded on. The newer
radiators have tabs that run the length of the top of the
rad. The old rads were only welded on over 3/4 of an inch
or so. My old radiator was replaced under warranty.
Shazam*
Radiator Fan
- My temp light came on at
approx. 814 km. and the bike has now gone in for it's
1000km (600mile)service and diagnosed as a defective fan
, just wondering if anyone else has had a similar
occurrence? PF in AB
- Mine ('01 GS) did the same
thing... the fuse had gone south within 150 miles of
picking it up. No problems since replacing the fuse.
Gerry #951.
- Temp light came on in death
valley, replaced fuse, blew again. Looked at the fan and
it was froze solid. Replaced under warranty, but a pain
out in the desert. MikeB #819
- I just replaced my fan this
weekend at 9000 miles. Warranty. Chris
- I now have my bike in the
shop for similar cooling system problems. I've roached
two fans with my bike, and multiple fuses. Bike still
gets hot at speed. Water Pump? Radiator? Both? Chris
- Chris went through two fan
motors that I know of on his GS and I lost my fan coming
out of Jasper , Alberta. Both of us were running the
Alcan 5000 and it was a strain on the bikes, but mine
didn't fail till after the race was over. I took my fan
motor apart and saw that it had heated up, melted the
winding insulation, which was slung onto the shaft and
brush assemblies, which when cooled down got hard and
froze up the shaft. Piss poor design!. New one now and
will see for how long. Skip
- The fan on my 01 GS died at
about 13K miles. I noticed it while riding slow and hard
off road when the overtemp idiot light came on. I was
able to back off to an easy pace and the light went out.
At the next stop I found the fan would not turn freely.
Thinking it had a rock stuck in it I forced it around.
This got it loose but that was not the problem. As stated
in the FAQ when the fans fail their inards melt and that
is what causes them to freeze up. The fan was replaced
under warranty by CalBMW who managed to get a fan sent
overnight while allowing me the use of one of their
loaner bikes. FYI they use the Moditec diagnostic tool to
determine if the fan is bad. I reconnected my O2 sensor
prior to taking it in and warned them they would find O2
faults (I use a Techlusion box). This seemed to make this
a non-issue for them. (BradG)
- If you suspect a fault in the
fan coming on, you must also test the fan thermoswitch.
It's one of the two thingies screwed into the thermostat
housing, the top one I think. Remove it, hang it in a pot
of water on your stove, connect your digital multimeter
to it's two terminal, set to ohms any range (or rig up
any continuity gadget eg some batteries and a light),
turn up the heat and observe at what temp you get
continuity (ie the switch has closed, thusmaking the fan
come on). The temp for it to come on is stamped on it,
mine says 95C if I recall correctly, and it closes at
exactly the stated temp. While you're at it, you might
want to also boil the thermostat. Don't forget to drain
some coolant before you open this area, or you will have
a slippery floor. (Aleksander in Dubai)
- Well, I'm not sure what kind
of coolant I have runnin' through my radiator. But I
guess it's working fine 'cause my d*mn fan is not working.
The thing is missing the bolts and resting against the
radiator. I have had the bike ('98 F650 with 10K miles,
three of which I have put on it) since Nov. '02. I have
never seen the temp light come on. Should I be worried? I
haven't run the bike hard yet. And that d*mn fan is gonna
cost $200+ I don't wanna take the thing to a dealer
but I can't find a manual!!! It's sitting in my garage
collecting dust... It's a Rotax engine! A lil' cooling
assist fan shouldn't be a big deal should it? Geronimo
- My fan died in exactly the
same way somewhere between 12 and 14,000 miles. Brad, N.
CA., 2001 F650GS - Inmate #1002
- I have 8600 miles on it, and
it's about 10 months old. (When the fan died-sic) Seacuke
#1214, '02 F650GS, California
